Display screen or portion thereof with transitional graphical user interface



FIG. 1 is a first image in a sequence for a display screen or portionthereof with transitional graphical user interface, showing our designin a first embodiment;

FIG. 2 is a second image in a sequence thereof;

FIG. 3 is a third image in a sequence thereof;

FIG. 4 is a fourth image in a sequence thereof;

FIG. 5 is a fifth image in a sequence thereof;

FIG. 6 is a sixth image in a sequence thereof;

FIG. 7 is a seventh image in a sequence thereof;

FIG. 8 is a first image in a sequence for a display screen or portionthereof with transitional graphical user interface, showing our designin a second embodiment;

FIG. 9 is a second image in a sequence thereof;

FIG. 10 is a third image in a sequence thereof;

FIG. 11 is a fourth image in a sequence thereof;

FIG. 12 is a fifth image in a sequence thereof;

FIG. 13 is a first image in a sequence for a display screen or portionthereof with transitional graphical user interface, showing our designin a third embodiment;

FIG. 14 is a second image in a sequence thereof; and,

FIG. 15 is a third image in a sequence thereof.

The broken lines showing the display screen or portion thereof andportions of the graphical user interface form no part of the claimeddesign.

The appearance of the transitional image sequentially transitionsbetween the images shown in FIGS. 1-7, 8-12 and 13-15. The process orperiod in which one image transitions to another image forms no part ofthe claimed design.

CLAIM The ornamental design for a display screen or portion thereof withtransitional graphical user interface, as shown and described.